1. Field of the Invention
The present invention relates to an information processing apparatus in a network environment based on Dynamic Host Configuration Protocol (DHCP), a control method for the information processing apparatus, and a computer-readable storage medium.
2. Description of the Related Art
Access to devices connected to networks, such as printers, from client personal computers (PCs) over the networks has been available. Several techniques for allowing a client PC to search for a device on a network have been available. In some techniques, a search server is provided on a network, and a client PC accesses the search server for query (for example, Japanese Patent Laid-Open No. 2004-62443). In such techniques, the search server has a database for providing centralized management of device information of individual devices connected to the network. Then, each time device information of a device is changed, the contents of the database are updated. For instance, when a device connected to the network is powered off or is disconnected from the network, device information of the device is deleted from the database.
Further, in recent years, in an environment where a plurality of nodes such as client PCs or devices are connected to a network, such network nodes have been often assigned Internet protocol (IP) addresses using a DHCP-based system. DHCP is a mechanism for dynamically assigning an IP address to a node connected to a network, such as a client PC or a device. In DHCP, a node assigned an IP address is referred to as a DHCP client and a server that assigns an IP address is referred to as a DHCP server. A DHCP client that wishes to be assigned an IP address issues a request to the DHCP server to obtain an IP address. The DHCP server manages the DHCP client that has issued the request and the IP address assigned to the requesting DHCP client. The DHCP client sends a notification for releasing the IP address to the DHCP server when the IP address is no longer necessary. Upon receiving the release notification, the DHCP server releases the assignment of the IP address to the DHCP client. As a result, this IP address can be assigned to another DHCP client, thus providing for effective use of a limited number of IP addresses.
In techniques of the related art, however, a DHCP client may omit the step of sending an IP address release notification to the DHCP server in order to, for example, speed up the shut down process of the client's machine.
In this case, the IP address assigned to the DHCP client by the DHCP server is still assigned to the DHCP client although it is no longer necessary (this DHCP client no longer exists). This can prevent effective use of IP addresses.
Moreover, in a case where a DHCP client is required to notify the server of a shutdown, an increased load is placed on the DHCP client when a plurality of servers such as a search server and a DHCP server exist.